Visualizing the U.S. National Park Service’s Inventory and Monitoring Program Data

Summary

I worked on a small team to build a Tableau-based data visualizations to allow users to sort through large tables of data about US National Park soil and vegetation. We followed a user-centered design process in which we interviewed and tested our designs with users, including experts in the field. Ultimately, we created a pair of dashboards in which users could filter large amounts of data to spot correlations and get details about individual items. The dashboards were built using data visualization best practices (such as using proper visual encoding methods and supporting ideal data interactions) learned in a graduate information visualization course at UW.

We created an HTML frame to contain the two dashboards and allow us to provide additional instruction.

Problem

For this project, we were tasked with choosing a data source and creating a Tableau visualization by following a user-centered design process and utilizing ideal data visualization techniques.

We began by locating a data source, which required researching the context of the data (how and why it was collected), finding related work, and exploring visualization possibilities in Tableau. We wanted to find a data set that was extensive and valuable but without strong existing visualizations. Eventually we chose a series of data sets from the United States National Park Service's Inventory and Monitoring Program. The data sets we chose contain vegetation data collected for several national parks across the United States. Each spreadsheet contained a list of land plots with all kinds of value for each, from topographic data (elevation, aspect, slope, etc.) to vegetation data (dominant plant type, alliance, etc.).

Our primary persona, a NPS scientists who wants to make correlations between variables and get an overview of multiple plots.
Our secondary persona, a NPS educator who wants to be able to share information with his guests.
Our tertiary persona, a teacher who wants to be able to teach his students about ecology.

Process

For our design process, we sketched out potential visualizations and dashboards, as well as explored the data extensively in Tableau. We learned what kinds of visualizations we would be able to support and created some prototypes that allowed for some interaction and exploration.

An early paper prototype/sketch for an overview dashboard.
An early paper prototype/sketch for a single-park view.
An early paper prototype/sketch for a single-plot view.A screenshot from an early prototype in which the user could view data about selected plots.
A screenshot from an early prototype in which the user has selected a single plot.

We conducted expert user interviews, including with one of the scientists from the National Park Service who was behind the data collection, by asking about the tasks they used the data for and by sharing the visualizations we had created at that point.

Our user interviews helped us refine our designs and identify new tasks to support. We iterated several times to ensure that our designs would fulfill the needs of the users we had interviewed.

Once we had a stable version that we felt met our users' needs, we conducted basic usability testing with both expert and non-expert users. With our expert users, we attempted to validate the utility of the dashboards for the tasks we needed to support. With non-expert users, we were mostly interested in testing the interface design since they couldn't comment on the usefulness of the dashboards. Through our testing, we found that our users could accomplish the tasks that we had provided them with, but that some of the labeling was insufficient and that there were some minor issues with the UI. We were able to resolve the minor issues that were uncovered during the usability testing without much trouble.

Results

Ultimately, we created an HTML page that allowed users to toggle between two dashboards: one to search for correlations between topographic and vegetation qualities, and one to learn more about individual plots of land. The HTML page allowed us to provide additional context, such as help text and term definitions, as well as some JavaScript interaction.

In addition, we wrote an in-depth paper documenting the entire process and results, and presented our visualization to our class.

Overall, I learned a lot about visualization 'best practices' and about how to use Tableau for creating visualizations.

A screenshot of our first dashboard, "Find Vegetation Qualities by Plot Properties"
A screenshot of our second dashboard, "Explore Table of Vegetation Plots"